U.S. patent number 8,684,404 [Application Number 13/612,931] was granted by the patent office on 2014-04-01 for air bag with variable venting.
This patent grant is currently assigned to TRW Vehicle Safety Systems Inc.. The grantee listed for this patent is Daniele Aranzulla, Martin Burkhardtsmaier, Kurt F. Fischer, Douglas M. Gould. Invention is credited to Daniele Aranzulla, Martin Burkhardtsmaier, Kurt F. Fischer, Douglas M. Gould.
United States Patent |
8,684,404 |
Fischer , et al. |
April 1, 2014 |
Air bag with variable venting
Abstract
An apparatus (10) for helping to protect an occupant (20) of a
vehicle (12) comprises an inflatable vehicle occupant protection
device (14) inflatable between a vehicle surface (36) and the
vehicle occupant. A vent (160) releases inflation fluid from the
protection device (14). The vent (160) has an actuated condition
and a non-actuated condition. A tether (150) has a first connection
with the vent (160) and a second connection with the protection
device (14). Tension on the tether (150) actuates the vent (160).
The vent (160) is initially in the non-actuated condition upon
initial deployment of the protection device (14). Further
deployment of the protection device (14) causes the tether (150) to
place the vent (160) in the actuated condition. Occupant
penetration into the protection device (14) causes the tether (150)
to place the vent (160) in the non-actuated condition.
Inventors: |
Fischer; Kurt F. (Leonard,
MI), Gould; Douglas M. (Lake Orion, MI), Aranzulla;
Daniele (Essingen, DE), Burkhardtsmaier; Martin
(Schwaebisch Gmund, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Fischer; Kurt F.
Gould; Douglas M.
Aranzulla; Daniele
Burkhardtsmaier; Martin |
Leonard
Lake Orion
Essingen
Schwaebisch Gmund |
MI
MI
N/A
N/A |
US
US
DE
DE |
|
|
Assignee: |
TRW Vehicle Safety Systems Inc.
(Washington, MI)
|
Family
ID: |
47596615 |
Appl.
No.: |
13/612,931 |
Filed: |
September 13, 2012 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20130026744 A1 |
Jan 31, 2013 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13482004 |
May 29, 2012 |
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13114349 |
May 24, 2011 |
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12912800 |
Oct 27, 2010 |
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Current U.S.
Class: |
280/739;
280/743.2 |
Current CPC
Class: |
B60R
21/2338 (20130101); B60R 21/239 (20130101); B60R
21/205 (20130101); B60R 2021/23382 (20130101); B60R
2021/2395 (20130101) |
Current International
Class: |
B60R
21/276 (20060101) |
Field of
Search: |
;280/743.2,739 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Verley; Nicole
Attorney, Agent or Firm: Tarolli, Sundheim, Covell &
Tummino LLP
Parent Case Text
RELATED APPLICATIONS
This application is a continuation in part of U.S. patent
application Ser. No. 13/482,004, filed May 29, 2012, which is a
continuation in part of U.S. patent application Ser. No.
13/114,349, filed May 24, 2011, which is a continuation in part of
U.S. patent application Ser. No. 12/912,800, filed Oct. 27, 2010.
Each of these related applications are hereby incorporated by
reference in their entireties.
Claims
Having described the invention, the following is claimed:
1. An apparatus for helping to protect an occupant of a vehicle,
the apparatus comprising: an inflatable vehicle occupant protection
device inflatable between a vehicle surface and the vehicle
occupant; a vent for releasing inflation fluid from the protection
device, the vent having an actuated condition and a non-actuated
condition; and a tether having a first connection with the vent and
a second connection with the protection device, tension on the
tether actuating the vent, wherein the vent is configured to be
initially in the non-actuated condition upon initial deployment of
the protection device, with further deployment of the protection
device to a predetermined degree causing the tether to place the
vent in the actuated condition, and the tether and vent being
configured such that a predetermined degree of occupant penetration
into the protection device causes the tether to place the vent back
in the non-actuated condition, wherein the vent comprises a vent
opening with a flow area that can be adjusted to throttle inflation
fluid flow through the vent, tension on the tether throttling the
vent.
2. The apparatus recited in claim 1, wherein the actuated condition
of the vent is an open condition and the non-actuated condition of
the vent is a closed condition.
3. The apparatus recited in claim 1, wherein the actuated condition
of the vent is a closed condition and the non-actuated condition of
the vent is an open condition.
4. The apparatus recited in claim 1, further comprising a guide
connected to the protection device, the tether extending through
the guide, wherein the guide is positioned on the protection device
to move with the protection device in response to occupant
penetration into the protection device, and wherein this guide
movement causes the tether to slide through the guide and thereby
throttle the vent.
5. The apparatus recited in claim 4, wherein the guide is
positioned on the protection device at a location where a
particular portion of the occupant is likely to strike the
protection device.
6. The apparatus recited in claim 4, wherein the proportion of
occupant penetration to vent throttling can be adjusted by
adjusting at least one of the position of the guide and the second
connection on protection device.
7. The apparatus recited in claim 1, wherein the vent is configured
such that inflation fluid pressure in the protection device biases
the vent toward the non-actuated condition and the tether urges the
vent toward the actuated condition against the bias of inflation
fluid pressure as the protection device inflated and deploys.
8. The apparatus recited in claim 1, wherein the tether is
configured such that tether movement in response to occupant
penetration causes vent throttling by permitting the vent to move
under the bias of inflation fluid pressure toward the non-actuated
condition.
9. The apparatus recited in claim 1, wherein the throttling of the
vent is in proportion to occupant penetration into the protection
device.
10. The apparatus recited in claim 1, wherein the vent is
configured to be placed in a closed condition in response to the
protection device reaching a fully deployed condition, the tether
throttling the vent toward the open condition in response to the
occupant penetration.
11. The apparatus recited in claim 1, wherein the vent is
configured to be placed in an open condition in response to the
protection device reaching a fully deployed condition, the tether
throttling the vent toward the closed condition in response to the
occupant penetration.
12. The apparatus recited in claim 1, wherein the second connection
comprises a guide connected to a front panel of the protection
device at a location where an occupant penetration into the
protection device is likely.
13. The apparatus recited in claim 1, wherein the second connection
is located on a front panel of the protection device at a location
where occupant penetration into the protection device is
likely.
14. The apparatus recited in claim 1, wherein the tether is
configured to prevent actuation of the vent in response to the
protection device being inhibited from deployment.
15. An apparatus for helping to protect an occupant of a vehicle,
the apparatus comprising: an inflatable vehicle occupant protection
device inflatable between a vehicle surface and the vehicle
occupant; a vent for releasing inflation fluid from the protection
device, the vent having an actuated condition and a non-actuated
condition; and a tether having a first connection with the vent and
a second connection with the protection device, fluid pressure
acting on the vent urges the vent toward the non-actuated condition
and tension on the tether urges the vent toward the actuated
condition, fluid pressure acting on the protection device in the
region of the second connection tensions the tether, which
overcomes the fluid pressure acting on the vent and places the vent
in the actuated condition, wherein the vent comprises a vent
opening with a flow area that can be adjusted to throttle inflation
fluid flow through the vent, tension on the tether throttling the
vent.
16. The apparatus recited in claim 15, wherein the tether is
configured such that occupant penetration into the protection
device allows the fluid pressure acting on the vent to urge the
vent toward the non-actuated condition.
17. The apparatus recited in claim 15, further comprising a guide
connected to the protection device, the tether extending through
the guide, wherein the guide is positioned on the protection device
to move with the protection device in response to occupant
penetration into the protection device, and wherein this guide
movement causes the tether to slide through the guide and thereby
throttle the vent.
18. The apparatus recited in claim 17, wherein the guide is
positioned on the protection device at a location where a
particular portion of the occupant is likely to strike the
protection device.
19. The apparatus recited in claim 15, wherein the throttling of
the vent is in proportion to occupant penetration into the
protection device.
20. The apparatus recited in claim 15, wherein the vent is
configured to be placed in a closed condition in response to the
protection device reaching a fully deployed condition, the tether
throttling the vent toward the open condition in response to the
occupant penetration.
21. The apparatus recited in claim 15, wherein the vent is
configured to be placed in an open condition in response to the
protection device reaching a fully deployed condition, the tether
throttling the vent toward the closed condition in response to the
occupant penetration.
22. The apparatus recited in claim 15, wherein the second
connection comprises a guide connected to a front panel of the
protection device at a location where occupant penetration into the
protection device is likely.
23. The apparatus recited in claim 15, wherein the second
connection is located on a front panel of the protection device at
a location where occupant penetration into the protection device is
likely.
24. The apparatus recited in claim 15, wherein the tether is
configured to prevent actuation of the vent in response to the
protection device being inhibited from deployment.
25. An apparatus for helping to protect an occupant of a vehicle,
the apparatus comprising: an inflatable vehicle occupant protection
device inflatable between a vehicle surface and the vehicle
occupant; a vent for releasing inflation fluid from the protection
device, the vent having an actuated condition and a non-actuated
condition, the vent being configured to be in the non-actuated
condition when the protection device deploys; and a tether having a
first connection with the vent and a second connection with the
protection device, the tether being configured to: prevent
actuation of the vent in response to the protection device being
inhibited from deployment; actuate the vent in response to
substantial deployment of the protection device; throttle actuation
of the vent through a range of deployment between initial
deployment and substantial deployment of the protection device; and
place the vent in the non-actuated condition in response to
occupant penetration into the protection device beyond a
predetermined degree.
Description
FIELD OF THE INVENTION
The invention relates to an apparatus for helping to protect an
occupant of a vehicle. More particularly, the invention relates to
an air bag inflatable between an instrument panel and a front seat
occupant of a vehicle.
BACKGROUND OF THE INVENTION
It is known to provide an inflatable vehicle occupant protection
device, such as an air bag, for helping to protect an occupant of a
vehicle. One particular type of air bag is a frontal air bag
inflatable between an occupant of a front seat of the vehicle and
an instrument panel of the vehicle. Such air bags may be driver air
bags or passenger air bags. When inflated, the driver and passenger
air bags help protect the occupant from impacts with parts of the
vehicle such as the instrument panel and/or a steering wheel of the
vehicle.
Passenger air bags are typically stored in a deflated condition in
a housing that is mounted to the vehicle instrument panel. An air
bag door is connectable with the housing and/or instrument panel to
help enclose and conceal the air bag in a stored condition. Upon
deployment of the passenger air bag, the air bag door opens to
permit the air bag to move to an inflated condition. The air bag
door opens as a result of forces exerted on the door by the
inflating air bag.
Driver air bags are typically stored in a deflated condition in a
housing that is mounted on the vehicle steering wheel. An air bag
cover is connectable with the housing and/or steering wheel to help
enclose and conceal the air bag in a stored condition. Upon
deployment of the driver air bag, the air bag cover opens to permit
the air bag to move to an inflated condition. The air bag cover
opens as a result of forces exerted on the cover by the inflating
driver air bag.
Another type of air bag is a side impact air bag inflatable between
a side structure of a vehicle and a vehicle occupant. Side impact
air bags may, for example, be seat mounted, side structure mounted,
or door mounted. Another type of air bag is an inflatable knee
bolster inflatable between an instrument panel and/or steering
column of a vehicle and a vehicle occupant. Inflatable knee
bolsters may, for example, be mounted in the instrument panel or on
the steering column.
Air bags may include vents for releasing inflation fluid from an
inflatable volume of the bag. Airbag vents may be used to control
pressurization of the air bag in response to vehicle and/or
occupant conditions at the time of deployment. The air bag vents
can thus help to produce a desired ride-down effect.
SUMMARY OF THE INVENTION
The invention relates to an apparatus for helping to protect an
occupant of a vehicle. The apparatus comprises an inflatable
vehicle occupant protection device inflatable between a vehicle
surface and the vehicle occupant. A vent releases inflation fluid
from the protection device. The vent has an actuated condition and
a non-actuated condition. A tether has a first connection with the
vent and a second connection with the protection device. Tension on
the tether actuates the vent. The vent is initially in the
non-actuated condition upon initial deployment of the protection
device. Further deployment of the protection device causes the
tether to place the vent in the actuated condition. Occupant
penetration into the protection device causes the tether to place
the vent in the non-actuated condition.
The present invention also relates to an apparatus for helping to
protect an occupant of a vehicle. The apparatus comprises an
inflatable vehicle occupant protection device inflatable between a
vehicle surface and the vehicle occupant. A vent for releasing
inflation fluid from the protection device has an actuated
condition and a non-actuated condition. A tether has a first
connection with the vent and a second connection with the
protection device. Fluid pressure acting on the vent urges the vent
toward a non-actuated condition. Tension on the tether urges the
vent toward an actuated condition. Fluid pressure acting on the
protection device in the region of the second connection tensions
the tether, which overcomes the fluid pressure acting on the vent
and places the vent in the actuated condition.
The present invention further relates to an apparatus for helping
to protect an occupant of a vehicle. The apparatus includes an
inflatable vehicle occupant protection device inflatable between a
vehicle surface and the vehicle occupant. A vent for releasing
inflation fluid from the protection device has an actuated
condition and a non-actuated condition. The vent is configured to
be in the non-actuated condition when the protection device
deploys. A tether has a first connection with the vent and a second
connection with the protection device. The tether is configured to
prevent actuation of the vent in response to the protection device
being inhibited from deployment and actuate the vent in response to
substantial deployment of the protection device. The tether is also
configured to throttle actuation of the vent through a range of
deployment between initial deployment and substantial deployment of
the protection device. The tether is further configured to place
the vent in the non-actuated condition in response to occupant
penetration into the protection device beyond a predetermined a
predetermined degree.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features of the invention will become
apparent to one skilled in the art to which the invention relates
upon consideration of the following description of the invention
with reference to the accompanying drawings, in which:
FIGS. 1 and 2 are schematic side views illustrating an apparatus
for helping to protect an occupant of a vehicle, according to an
aspect of the invention;
FIG. 3 is a chart illustrating certain occupant characteristics
under different vehicle operating conditions;
FIGS. 4A-4C are schematic views illustrating different conditions
of the apparatus of FIGS. 1 and 2;
FIG. 5 is a chart illustrating certain occupant characteristics
under different vehicle operating conditions and corresponding vent
conditions associated with the vent configuration of FIGS.
4A-4C;
FIGS. 6A-6C are schematic views illustrating different conditions
of an apparatus having a different configuration;
FIG. 7 is a chart illustrating certain occupant characteristics
under different vehicle operating conditions and corresponding vent
conditions associated with the vent configuration of FIGS.
6A-6C;
FIG. 8 is an enlarged view of a portion of the apparatus;
FIGS. 9A-9C are enlarged views of a portion of the apparatus in
different conditions, according to an embodiment of the
invention;
FIGS. 10A-10C are enlarged views of a portion of the apparatus in
different conditions, according to an embodiment of the
invention;
DETAILED DESCRIPTION OF THE INVENTION
An apparatus 10 for helping to protect an occupant 20 of a vehicle
12 includes an inflatable vehicle occupant protection device 14 in
the form of an air bag. In the embodiment illustrated in FIGS. 1
and 2, the air bag 14 is a passenger frontal air bag for helping to
protect an occupant 20 of a seat 22 on a passenger side 24 of the
vehicle 12. As shown in FIGS. 1 and 2, the vehicle 12 also includes
a seatbelt 18 for helping to protect the vehicle occupant 20.
The air bag 14 may be part of an air bag module 30 that includes an
inflator 32 and a housing 34. The air bag 14 has a stored
condition, indicated by dashed lines in FIG. 1, in which the air
bag is folded and placed in the housing 34. The module 30 is
mounted to a dash or instrument panel 36 of the vehicle 12. The
housing 34 helps contain and support the air bag 14 and inflator 32
in the instrument panel 36.
An air bag door 40 is releasably connected to the instrument panel
36 and/or the housing 34. In a closed condition (not shown), the
air bag door 40 forms a cover for the module 30 and helps enclose
the air bag 14 in the stored condition in the housing 34. The door
40 is movable to an opened condition illustrated in FIG. 1 to
uncover an opening 44 through which the air bag 14 may be deployed
from the stored condition in the housing 34. The door 40 may be
connected to the vehicle 12, e.g., the instrument panel 36, either
directly or through the housing 34, by means (not shown), such as a
plastic hinge portion, a strap, or a tether.
The inflator 32 is actuatable to provide inflation fluid to an
inflatable volume 54 of the air bag 14 to deploy the air bag to the
inflated condition. The inflator 32 may be of any known type, such
as stored gas, solid propellant, augmented, or hybrid. The
apparatus 10 includes a sensor, illustrated schematically at 50,
for sensing an event for which inflation of the air bag 14 is
desired, such as a collision. The inflator 32 is operatively
connected to the sensor 50 via lead wires 52.
The air bag 14 can be constructed of any suitable material, such as
nylon (e.g., woven nylon 6-6 yarns), and may be constructed in any
suitable manner. For example, the air bag 14 may include one or
more pieces or panels of material. If more than one piece or panel
is used, the pieces or panels may be interconnected by known means,
such as stitching, ultrasonic welding, heat bonding, or adhesives,
to form the air bag. The air bag 14 may be uncoated, coated with a
material, such as a gas impermeable urethane, or laminated with a
material, such as a gas impermeable film. The air bag 14 thus may
have a gas-tight or substantially gas-tight construction. Those
skilled in the art will appreciate that alternative materials, such
as polyester yarn, and alternatives coatings, such as silicone, may
also be used to construct the air bag 14.
Upon sensing the occurrence of an event for which inflation of the
air bag 14 is desired, such as a vehicle collision, the sensor 50
provides a signal to the inflator 32 via the lead wires 52. Upon
receiving the signal from the sensor 50, the inflator 32 is
actuated and provides inflation fluid to the inflatable volume 54
of the air bag 14 in a known manner. The inflating air bag 14
exerts a force on the door 40, which moves the door to the opened
condition. The air bag 14 inflates from the stored condition to a
deployed condition, such as the fully inflated, deployed, and
pressurized condition illustrated in solid lines in FIG. 1. The air
bag 14, while inflated, helps protect the vehicle occupant 20 from
impacts with parts of the vehicle 12, such as the instrument panel
36 and/or steering wheel (not shown).
The air bag 14, when deployed in response to an event for which
occupant protection is desired, helps protect the occupant 20 by
helping to absorb the force of impact placed on the air bag by the
occupant. When the occupant 20 impacts the air bag 14, the occupant
penetrates into the air bag, which absorbs and distributes the
impact forces throughout the large area and volume of the bag. By
"penetrates" into the air bag 14, it is meant to refer to the
instance where, in the case of a frontal impact to the vehicle 12,
the occupant is moved forward, as indicated by the arrow labeled 42
in FIGS. 1 and 2, into engagement with the air bag 14.
The "penetration" of the occupant into the air bag 14 is the
distance or degree to which the occupant 20 moves into the inflated
depth of the air bag. In other words, the degree of penetration
could be measured as the distance the penetrating occupant 20 moves
a given point on a front panel 74 of the air bag 14 toward the
instrument panel 36. For example, penetration could be measured as
the distance between a point on the front panel 74 and a fixed
point on the instrument panel 36 or between a point on the occupant
20 (e.g., the occupant's chest) and a fixed point on the instrument
panel.
Several factors determine the degree to which an occupant 14
penetrates the air bag 14. For example, the size or mass of the
occupant 20, the speed at which the occupant strikes the air bag
14, the pressurization of the air bag, the seat position
(forward/rearward, upright/reclined), and whether or not the
occupant is restrained by the seatbelt 18 all help determine the
degree to which the occupant penetrates the air bag in a given
deployment scenario. Some of these determining factors are
illustrated in FIG. 3, which depicts chest to instrument panel air
bag penetration for occupants that are different in size, that are
belted versus unbelted, and that strike the air bag 14 at different
speeds.
FIG. 3 illustrates penetration values for two differently sized
occupants--a 50.sup.th percentile male occupant (50% male) and a
5.sup.th percentile female occupant (5% female). The 50% male is
derived from statistical values for the U.S. male population. The
50% male has the mean height and weight of the male U.S.
population, meaning that roughly half of the U.S. male population
is taller/heavier and roughly half of the U.S. male population is
shorter/lighter. The 50% male is thus an average or medium sized
male occupant, and thus would typically adjust his vehicle seat to
a middle position, especially when driving the vehicle. The 5%
female is derived from statistical values for the U.S. female
population. The 5% female has a mean height and weight that, is
taller/heavier than only roughly 5% of the U.S. female population.
Conversely, this means that roughly 95% U.S. female population is
taller/heavier than the 5% female. The 5% female is thus a small
female occupant, and thus would typically adjust her vehicle seat
to a forward position, especially when driving the vehicle.
FIG. 3 illustrates that whether the occupant is belted versus
unbelted has an effect on occupant penetration into the air bag. In
the tests used to produce the data shown in FIG. 3, the seat
position of the 5% female is more than 50 mm forward of the seat
position of the 50% male. As shown in FIG. 3, an unbelted 5% female
occupant travelling at 25 mph penetrates the air bag over
approximately 150 mm more than a belted 5% female occupant
traveling at 35 mph. Similarly, an unbelted 50% male occupant
travelling at 25 mph penetrates the air bag well over 200 mm more
(approximately 225 mm) than a belted 50% male occupant traveling at
35 mph. In fact, the unbelted 5% female traveling at 25 mph
penetrates the air bag approximately 150 mm more than the belted
50% male occupant traveling at 35 mph.
Those skilled in the art will appreciate that much can be
extrapolated from belted/unbelted data illustrated in FIG. 3. For
example, a 50% 25 mph unbelted male will strike through the air bag
and impact the instrument panel. A 5% 25 mph unbelted female will
come within 50 mm of striking through the air bag and impacting the
instrument panel. Due to the differing seat positions for the
occupants, belted 50% male and 5% females travelling at 35 mph will
come within about 200 mm of striking through the air bag and
impacting the instrument panel. It will thus be appreciated that
the difference between striking through and cushioning can be a
matter of relatively short distances/positions. For example, if the
seat position of the 50% male is 100 mm closer, the difference
between strikethrough and non-strikethrough is 100 mm, which can
easily be taken up if the occupant is somewhat taller or heavier,
if the seatbelt is somewhat loose, or if the vehicle is travelling
at a somewhat higher rate of speed. It thus becomes very difficult
to respond actively to the vast number of combinations of occupant
size/weight, seat position, vehicle speed, and buckle conditions
that may be present at the time of air bag deployment.
To account for this, the air bag 14 may have one or more actuatable
features for helping to control or tailor inflation, deployment,
and pressurization of the air bag in response to vehicle
conditions, occupant conditions, or both vehicle and occupant
conditions. These features are actuatable passively in response to
vehicle and occupant conditions at the time of inflation. Thus, in
the illustrated embodiments, these features are actuatable without
relying on active sensors and/or actuators, such as electrical or
pyrotechnic actuators.
Referring to FIGS. 1 and 2, the air bag 14 includes a tether 150
for actuating a vent 160 for releasing inflation fluid from the
inflatable volume 54 of the air bag 14. The tether 150 is adapted
to actuate the vent 160 depending on vehicle or occupant conditions
in the vehicle 12 both at the time of deployment and during air bag
14 deployment. In the embodiment of FIGS. 1 and 2, the adaptive
tether 150 comprises a single length of tether material that has a
first connection 162 connecting a first end portion 152 of the
tether. The first connection 162 may, for example, connect the
first end portion 152 of the tether 150 to a rear panel 72 of the
air bag 14 or to a portion of the air bag module 30, such as the
housing 34. The tether 150 has a second connection 164 connecting a
second end portion 154 of the tether. The second connection 164
may, for example, connect the second end portion 154 of the tether
150 to the vent 160.
The tether 150 extends through a guide 156 that is connected to the
air bag 14. In the embodiment of FIGS. 1 and 2, the guide 156 is
mounted on a front panel 74 of the air bag 14. The guide 156
anchors the tether 150 to the air bag and permits the tether 150 to
slide or otherwise move through its structure. The guide 156
divides the tether 150 into a first segment 166 and a second
segment 168.
The guide 156 may take various forms. Referring to FIG. 8, the
guide 156 may, for example, comprise a piece or loop of material,
such as air bag fabric, that is secured to a panel of the air bag
14 by means such as stitching 158. Alternative means for connecting
the guide 156 to the air bag 14 include ultrasonic welding,
adhesives, and heat bonding, and mechanical fasteners. The guide
156 may have alternative constructions and/or configurations. For
example, instead of a piece or loop of material, the guide 156 may
have a metal or plastic construction. Guides having this
construction may, for instance, be in the form of a metal/plastic
D-ring or a metal/plastic eyelet or grommet reinforcing a hole or
aperture in a fabric material. As another example, the guide 156
may be configured as a part of the air bag housing 34, in which
case the guide may comprise a ring or aperture formed in or
connected to the housing structure.
The adaptive tether 150 functions in cooperation with the guide 156
to be responsive to vehicle conditions, occupant conditions, or
both vehicle conditions and occupant conditions to control
actuation of the vent 160. Particularly, the tether 150 throttles
the vent 160 to help adapt the inflation, deployment,
configuration, shape, pressurization, or a combination thereof, of
the air bag 14. In the embodiment of FIGS. 1 and 2, this control is
implemented passively through the physical construction and
configuration of the air bag 14 and the adaptive tether 150, the
guide 156, and the vent 160.
In particular, in the embodiment of FIGS. 1 and 2, the air bag 14,
adaptive tether 150, guide 156, and vent 160 are constructed,
configured, and arranged to throttle the vent and thereby adapt the
inflation, deployment, and pressurization of the air bag 14
depending on the penetration of the occupant into the air bag 14.
This is beneficial because vehicle/occupant conditions, such as the
occupant size/weight, whether the occupant is belted or unbelted,
the occupant's seat position (forward/rearward, upright/reclined),
and the vehicle speed all affect the degree of occupant penetration
into the air bag. By adapting the air bag 14 passively in response
to occupant penetration, there is no need for an active
determination of all of these factors because all of these factors
are accounted for inherently and automatically through the
configuration and construction of the air bag.
In describing the function of the vent 160, the terms "actuated,"
"non-actuated," and "throttled" are used to identify different
conditions of the vent. The actuated condition of the vent 160
refers to the condition of the vent when the tether 150 is fully
tensioned due, for example, to full or substantially full
deployment of the air bag 14. The non-actuated condition of the
vent 160 refers to the condition of the vent when the tether has
not been tensioned due to air bag deployment to an extent
sufficient to cause any significant change in inflation fluid flow
through the vent. The throttled condition of the vent 160 refers to
the condition of the vent where air bag displacement has been
blocked, e.g., due to an out-of-position occupant, or altered,
e.g., due to an occupant penetrating into the air bag, such that
inflation fluid flow through the vent is altered.
FIG. 1 illustrates (in solid lines) an occupant 20, such as a 50%
male, in a normally seated and belted condition with the vehicle
seat 22 in an upright mid-positioned (i.e., between full rear and
full forward) condition. As shown in FIG. 1, in the illustrated
case of a belted 50% male occupant 20, the seatbelt 18 serves to
help restrain the occupant 20. As a result, the belted occupant 20
is restrained from moving toward the instrument panel 36. This
allows the air bag 14 to inflate and deploy with comparatively
little resistance or inhibition from the occupant 20 to a fully
inflated and deployed condition. The tether 150 is thus tensioned
and places the vent 160 in its actuated condition. In FIG. 1, as
shown generally at 20', the belted occupant may bend forward and
penetrate somewhat into a middle portion 100 or upper portion 102
of the air bag 14.
The guide 156 does not move significantly in response to upper body
penetration of the mid-positioned belted 50% male occupant 20. As
shown in FIG. 1, however, the degree or distance to which the
occupant 20' penetrates into the air bag 14 may be comparatively or
relatively small. If circumstances, such as the severity of the
event, the tightness of the seatbelt 18, or the position of the
occupant 20 at the time the event occurs, result in further
penetration of the occupant, the guide 156 may move toward the
instrument panel 36 and the vent 160 may be throttled. Otherwise,
the vent 160 may remain in its (fully) actuated condition and the
air bag 14 is left to provide its intended cushioning and ride down
effect.
In the illustration of FIG. 1, the occupant 20 does not penetrate
significantly into the portion of the air bag 14 where the guide
156 is located. Therefore, in the case of the 50% male occupant
illustrated in FIG. 1, the portion of the air bag 14 including the
guide 156 deploys fully, the tether 150 becomes tensioned, and the
tensioned tether 150 actuates the vent 160. This can be compared to
the small occupant, such as a 5% female, which is shown in dashed
lines at 20''.
FIG. 2 illustrates (in solid lines) an occupant 20, such as a 5%
female, in a normally seated and belted condition with the vehicle
seat 22 in an upright forward positioned condition. The conditions
in FIG. 2 are identical to those of FIG. 1, except the occupant is
smaller and the seat is in the forward position. In FIG. 2, the
seatbelt 18 serves to help restrain the occupant 20 from moving
toward the instrument panel 36. As shown in dashed lines at 20',
similar to FIG. 1, the belted 5% female occupant may bend forward
and penetrate into the air bag 14.
FIG. 2 illustrates that the forward position of the vehicle seat 22
can make a significant difference in the deployment of the air bag
14. The forward position of the vehicle seat 22 positions the
occupant 20 closer to the instrument panel 36 such that the
occupant blocks the air bag 14 from reaching the fully inflated and
deployed position. Therefore, other conditions being equal, the 5%
female occupant of FIG. 2 can experience penetration to a
comparatively greater extent than the 50% male occupant (shown in
dashed lines at 26). As a result, in the case of the 5% female
occupant illustrated in FIG. 2, the air bag 14 and guide 156 can be
are blocked from reaching full deployment. As a result, the tether
150 may not fully actuate the vent 160. The vent 160 is thus
throttled passively in accordance with the vehicle and occupant
conditions that position the occupant 20 as shown in FIG. 2.
Those skilled in the art will appreciate that the difference in the
fore/aft seat position between the 50% male in FIG. 1 and the 5%
female in FIG. 2 may not be large. The difference may, for example,
be as little as 50 mm. Since, however, it is the small, forward
positioned 5% female (FIG. 2) that penetrates further into the air
bag 14, it is desirable to ensure that the vent 160 is throttled
effectively and reliably. It is equally desirable that the vent 160
throttles differently in the case of the large mid/rear positioned
50% male occupant (FIG. 1) that does not penetrate significantly
into the air bag 14. This can be difficult, given the small
difference in the positions of the two occupants.
To account for this, the combination of the guide 156 and tether
150 allow not only for throttling the vent 160, but also for
adjusting the sensitivity of the throttling. The vent 160 has an
open condition (e.g., full-open), a closed condition (e.g.,
full-closed), and conditions between these two extremes in which
the vent is partially opened/closed. "Throttling" as used herein is
meant to refer to the fact that the degree to which the tether 150,
being configured for displacement and/or tension adjustments in
response to occupant penetration, correspondingly controls, i.e.,
throttles, the degree to which the vent is opened/closed. As the
vent 160 moves between the full open and full closed condition and
vice versa, the degree to which the vent is actuated (i.e., %
opened or % closed) changes.
"Throttling sensitivity" as used herein is meant to the degree or
rate at which the vent 160 is throttled in response to a given
change in displacement/tension of the tether 150. As described
above, displacement of the tether 150 corresponds on the degree of
occupant penetration into the air bag 14 at the location where the
guide 156 is connected. Thus, a tether 150 and vent 160
configuration with comparatively high throttling sensitivity would
produce a comparatively large change in vent throttling in response
to a given change in tether displacement/tension. Similarly, a
tether 150 and vent 160 configuration with comparatively low
throttling sensitivity would produce a comparatively small change
in vent throttling in response to the same given change in tether
displacement/tension. In this description, the throttling
sensitivity is quantified as a ratio of tether displacement to air
bag penetration distance (D.sub.T:D.sub.P).
In the embodiment shown in FIGS. 1 and 2, the tether 150 and guide
156 are configured such that the first and second segments 166 and
168 extend at a small acute angle (tether angle .alpha.) relative
to each other. If the segments 166 and 168 were configured to
extend parallel to each other, it would be easy to recognize that
occupant penetration into the air bag 14 that results in movement
of the guide 156 of X millimeters toward the instrument panel 36
would produce a corresponding change in tether 150 displacement of
2X millimeters. Thus, according to the invention, the tether 150
and guide 156 are configured to produce a comparatively high
throttling sensitivity, approaching 2:1 (D.sub.T:D.sub.P). This
high throttling sensitivity allows for throttling the vent 160 in a
manner that is highly sensitive and responsive to differing air bag
penetrations. Thus, referring to the embodiment illustrated in
FIGS. 1 and 2, this allows the tether 150 and guide 156 to
differentiate and respond to the 50% male and 5% female differently
even though the difference in positioning may be slight.
The throttling sensitivity of the tether 150 and vent 160
configuration can be adjusted by changing or adjusting the angle
.alpha. at which the tether extends from the guide 156. In the
single guide configuration of FIGS. 1 and 2, the sensitivity is
maximized by configuring the tether segments 166 and 168 as close
to parallel as possible, thus producing a throttling sensitivity
that approaches 2:1 (D.sub.T:D.sub.P). To decrease the throttling
sensitivity, the tether 150 and vent 160 combination are
adjusted/configured so that the angle .alpha. is increased. As the
angle .alpha. increases, the throttling sensitivity decreases, and
the degree to which the tether 150 throttles the vent 160 for a
given occupant penetration decreases.
In the embodiments of FIGS. 1 and 2, it should be noted that the
tether 150 remains tensioned even though, in FIG. 2, the occupant
20 penetrates the air bag 14 and moves the guide 156. This is
because the vent 160 itself takes up the slack in the tether 150 as
the occupant 20 penetrates the air bag 14 and the vent is throttled
between the fully open and fully closed position. This is
illustrated in FIGS. 4A-4C.
Referring to FIG. 4A, When the air bag 14 is fully inflated and
deployed, the tether 150 becomes fully tensioned and fully actuates
the vent 160. The vent 160 is configured such that an actuatable
vent part (not shown in FIGS. 4A-4C) that controls fluid flow
through the vent is urged to move in response to inflation fluid
pressure in the air bag 14. Inflation fluid pressure in the air bag
14 urges the vent 160 toward the non-actuated condition. The tether
150 is configured such that tension on the tether urges the
actuatable vent part toward the actuated condition against
inflation fluid pressure in the air bag 14. Thus, when the air bag
14 is fully inflated and deployed, the tether 150 overcomes the
urging that inflation fluid pressure places on the vent member and
places the vent 160 in the fully actuated condition. When the vent
160 is throttled due to occupant penetration, the tether 150 is
tensioned between the front panel 74 (FIGS. 1 and 2) of the air bag
14, the anchor point 162, and the vent 160.
Referring to FIG. 4B, as the occupant 20 penetrates the air bag 14
and begins displacing the guide 156, the tether 150 is displaced
and the actuatable vent member is permitted to move in response to
fluid pressure in the air bag 14, thus throttling the vent 160. As
the vent 160 throttles between the actuated and non-actuated
conditions, the tension on the tether 150 is maintained. As the
degree of occupant penetration increases, the throttling of the
vent 160 adjusts accordingly.
Referring to FIG. 4C, once the occupant 20 penetrates the air bag
14 to a degree such that the vent 160 is throttled to the
non-actuated condition, tension on the tether 150 is released. At
this point, since the vent 160 is in the non-actuated condition,
further penetration does not affect the vent. If, for some reason,
the occupant 20 moves in a direction that reverses the penetration,
and inflation fluid pressure in the air bag 14 is still sufficient,
the tether 150 could again become tensioned and vent 160 throttling
could resume.
The vent 160 may be configured such that the actuated condition of
the vent is either an open condition or a closed condition. In this
description, an "actuated open" vent is closed at the time of
deployment, and unrestricted air bag deployment tensions the tether
and actuates the vent (substantially or fully) opened. Occupant
penetration into the protection device throttles the vent back
towards the closed condition. Additionally, in this description, an
"actuated closed" vent is open at the time of deployment, and
unrestricted air bag deployment tensions the tether and actuates
the vent (substantially or fully) closed. Occupant penetration into
the protection device throttles the vent back towards the open
condition. Those skilled in the art will appreciate that the
selection of a actuated open or actuated closed vent configuration
can be based on a variety of factors, such as the position of the
air bag (driver frontal/passenger frontal) and the desired
cushioning and ride down characteristics.
The vent 160 may have any actuated open or actuated closed
configuration that is capable of performing with the tether 150 to
provide throttled venting in accordance with the description set
forth above. For purposes of illustration, an example of an
actuated open vent is illustrated in FIGS. 9A-9C and an example of
an actuated closed vent is illustrated in FIGS. 10A-10C. The
actuated, non-actuated, and throttled conditions of the vents of
FIGS. 9A-9C and 10A-10C correspond to the vehicle and occupant
conditions illustrated in FIGS. 4A-4C according to table 1:
TABLE-US-00001 TABLE 1 Actuated Actuated Vent Open Vent Closed Vent
Corresponding Condition FIGS. 9A-9C FIGS. 10A-10C Figure Actuated
Open Closed FIG. 4A Throttled In Between In Between FIG. 4B
Non-Actuated Closed Open FIG. 4C
Referring to FIGS. 9A-9C, the vent 160 is an actuated open vent 200
that is actuatable to release inflation fluid from the air bag 14.
In this embodiment, inflation fluid pressure in the air bag 14 acts
to place/maintain the vent 200 in the open condition at the time of
deployment. The structure of the actuated open vent 200 is
illustrated schematically in FIGS. 9A-9C. The vent 200 has a
generally conical configuration forming a conduit that extends
through an opening 216 in a wall 214 of the air bag 14. The opening
216 has a shape that mates with the cross-sectional shape of the of
the vent 200 at its interface with the wall 214. Thus, in the
embodiment of FIGS. 9A-9C, the opening 216 in the air bag wall 214
is circular.
Referring to FIGS. 9A-9C, the vent 200 comprises a first portion
comprising a conical inner wall 202 and a second portion comprising
a frusto-conical outer wall 204. The inner and outer walls 202 and
204 share a common central axis 206. As shown in FIGS. 9A-9C,
respective base portions 210 and 212 of the inner and outer walls
202 and 204 meet each other at the air bag wall 214, where they are
connected to the air bag 14 about the periphery of the opening 216
in the wall 214. As shown in FIGS. 9A-9C, the inner and outer walls
202 and 204 may have congruent or substantially congruent
configurations in which their respective base portions 210 and 212
have equal or substantially equal diameters, and the respective
walls extend at equal or substantially equal angles with respect to
the common axis 206.
The inner wall 202 tapers down from the base portion 210 and
extends away from the air bag wall 214 into the inflatable volume
of the air bag 14. The outer wall 204 tapers down from the base
portion 212 and extends away from the air bag wall 214 and away
from the air bag 14 outside the inflatable volume of the air bag
14. The frusto-conical outer wall 204 has an open end portion 220
that defines an outlet 222 of the vent 200. The outer wall 204
defines a passage or discharge chamber 234 through which inflation
fluid may travel en route to the outlet 222. The inner wall 202 has
a closed end portion 224 to which a first end portion of a tether
150 is connected. The inner wall 202 thus acts as an actuatable
vent member. The inner wall 202 includes a plurality of vent
openings 232 spaced about the circumference of the inner wall. In
the embodiment illustrated in FIGS. 9A-9C, the openings 232 have a
generally circular shape. The openings 232 could, however, have
alternative configurations. For example, the openings could
comprise elongated slots, X-shaped slits, cross-shaped slits,
T-shaped slits, Y-shaped slits, or other suitably shaped
openings.
The actuated open vent 200 has an actuated open condition
illustrated in FIG. 9A, a throttled intermediate condition
illustrated in FIG. 9B, and a non-actuated closed condition
illustrated in FIG. 9C. In the actuated open condition of FIG. 9A,
the tether 150 actuates the vent 200, tensioning or otherwise
pulling/maintaining the inner wall 202 in an open condition
positioned at least partially within the inflatable volume 54 of
the air bag 14. The tensioned tether 150 acts against inflation
fluid pressure in the air bag 14, which urges the inner wall
outward toward the closed condition of FIG. 9C. The tether 150 is
fully tensioned and is not displaced by a penetrating occupant. The
condition of the vent 200 illustrated in FIG. 9A thus corresponds
to the fully inflated and deployed condition illustrated in FIG. 4A
and described in reference to FIGS. 4A-4C. In this condition, the
tether 150 substantially or completely prevents the inner wall 202
from entering the discharge chamber 234. In the open condition,
fluid communication is established between the inflatable volume 54
and the atmosphere surrounding the air bag 14 via the vent openings
232, the discharge chamber 234, and the outlet 222.
In the throttled condition of FIG. 9B, tension on the tether 150 is
maintained but, due to a penetrating occupant, the air bag 14 has
not reached the fully inflated and deployed condition. The
condition of the vent 200 illustrated in FIG. 9B thus corresponds
to the partial occupant penetration condition illustrated in FIG.
4B and described in reference to FIGS. 4A-4C. Due to the
configuration of the vent 200, the pressure of inflation fluid in
the air bag 14 urges the inner wall 202 into the discharge chamber
234. In the condition of FIG. 4B, the inner wall 202 is placed in a
throttled condition in which the inner wall is partially inverted
into the discharge chamber 234, blocking a portion of the vent
openings 232 (shown in dashed lines) and leaving open the remaining
vent openings (shown in solid lines). The vent 200 thus throttles
inflation fluid flow through the partially blocked/partially
unblocked openings 232. The pressure of inflation fluid in the air
bag 14 presses the inner wall 202 against the blocked openings 232
and thereby forms an effective seal for blocking flow through those
openings.
In the closed condition of FIG. 9C, the tether 150 does not tension
or otherwise pull/maintain the inner wall 202 in the open condition
positioned within the inflatable volume 54 of the air bag 14. The
non-actuated condition of the vent 200 illustrated in FIG. 9C thus
corresponds to the high occupant penetration condition illustrated
in FIG. 4C and described in reference to FIGS. 4A-4C. The inner
wall 202 is thus free to move in response to inflation fluid
pressure in the inflatable volume 54 of the air bag 14. Under the
pressure of inflation fluid in the inflatable volume 54, the inner
wall 202 moves to a closed condition positioned at least partially
within the discharge chamber 234 defined by the outer wall 204. In
the closed condition, the inner wall 202 is inverted from the open
condition. Since the inner wall 202 and outer wall 204 have
congruent or substantially congruent configurations, the inner wall
202 when in the closed condition mates with, overlies, and follows
the contour of the outer wall 204, thereby forming a tight and
close fit between the walls. Inflation fluid pressure in the air
bag 14 maintains this fit and the resulting seal that blocks
inflation fluid flow through the openings 232.
In the closed condition of the vent 200, the vent openings 232 are
positioned against corresponding portions of the outer wall 204.
Since the conical inner wall 202 is closed at the end portion 224,
the inflation fluid pressure in the air bag presses the portions of
the inner wall 202 surrounding the vent openings 232 against the
corresponding portions of the outer wall 204. As a result, the
outer wall 204 constrains the inner wall 202 and blocks or
substantially blocks fluid communication between the inflatable
volume and the atmosphere surrounding the air bag 14. Inflation
fluid venting is thus blocked in the non-actuated, closed condition
of the vent 200.
Referring to FIGS. 10A-10C, the vent 160 is an actuated closed vent
260 that is actuatable to retain inflation fluid in the air bag 14.
In this embodiment, inflation fluid pressure in the air bag 14 acts
to place/maintain the vent 260 in the closed condition at the time
of deployment. The structure of the actuated closed vent 260 is
illustrated schematically in FIGS. 10A-10C. The vent 260 includes
one or more vent openings 262 formed in a panel 264, such as a side
panel, of the air bag 14. A vent door 266 is secured to the side
panel 264 and covers the openings 262. The tether 150 has a first
end portion secured to the vent door 266, and extends through a
guide 268 that is secured to the air bag panel 264. The vent door
266 thus acts as an actuatable vent member.
The vent door 266 is secured to the panel 264 by known means, such
as stitching, ultrasonic welding, heat bonding, or adhesives. In
the illustrated embodiment, the vent door 266 itself includes
separate panels 270 of material that are secured to each other by
known means, such as stitching, to give the vent door the
illustrated configuration. Those skilled in the art will appreciate
that the vent door 266 could have alternative single panel or
multiple panel constructions.
The vent door 266 has one or more vent openings 272 formed therein.
In the embodiment illustrated in FIGS. 10A-10C, the vent door 266
includes two vent openings 272. The tether 150 is secured to a
strip 274 of material of the vent door 266 that is positioned
between the vent openings 272. The strip 274 interconnects opposing
cover flaps 276 of the vent door 266.
The actuated closed vent 260 has an actuated closed condition
illustrated in FIG. 10A, a throttled intermediate condition
illustrated in FIG. 10B, and a non-actuated open condition
illustrated in FIG. 10C. In the closed condition of FIG. 10A, the
vent 260 has a closed condition in which the tether 150 is
tensioned and not displaced by a penetrating occupant. The
condition of the vent 260 illustrated in FIG. 10A thus corresponds
to the fully inflated and deployed condition illustrated in FIG. 4A
and described in reference to FIGS. 4A-4C. In the closed condition
of FIG. 10A, the tensioned tether 150 is forced by the guide 268 to
extend along the air bag panel 264. In this condition, the cover
flap portions 276 of the vent door 266 are tensioned along the air
bag panel 264. The shape and size of the cover flap portions 276
are configured such that, when tensioned along the air bag panel
264, they close the vent openings 272 of the vent door 266 and
cover the opening 262 in the air bag panel 264. In the closed
condition of the vent 260, the vent door 266 thus blocks inflation
fluid from exiting the air bag 14.
In the throttled condition of FIG. 10B, the tether 150 is
tensioned, but somewhat displaced by a penetrating occupant. The
condition of the vent 260 illustrated in FIG. 10B thus corresponds
to the partial occupant penetration condition illustrated in FIG.
4B and described in reference to FIGS. 4A-4C. In the throttled
condition of FIG. 10B, the tensioned tether 150 is forced by the
guide 268 to extend along the air bag panel 264. In this condition,
the displacement of the tether 150 caused by the partial
penetration of the occupant permits the cover flap portions 276 of
the vent door 266 to bulge outward partially and assume a somewhat
convex configuration. This allows the cover flap portions 276 of
the vent door 266 to partially open the vent openings 272 under the
pressure of inflation fluid in the air bag 14. Thus, in the
throttled condition of FIG. 10B, the vent 260 vents inflation fluid
at a reduced, i.e., throttled, flow rate.
In the open condition of FIG. 10C, due to displacement by a
penetrating occupant, the tether 150 is not tensioned. The
condition of the vent 260 illustrated in FIG. 10C thus corresponds
to the high occupant penetration condition illustrated in FIG. 4C
and described in reference to FIGS. 4A-4C. In the opened condition
of FIG. 10C, the tether 150 is relaxed or slacked, thereby
permitting the cover flap portions 276 of the vent door 266 to
bulge outward fully and assume a convex configuration. In this
condition, the vent openings 272 are opened due to the pressure of
inflation fluid in the air bag 14 and thereby release inflation
fluid from the air bag 14 through the openings 262 and 272.
According to the invention, the air bag 14, vent 160, and tether
150 configurations disclosed herein advantageously are configured
and tailored for multi-phase adaptive venting. The construction of
the vent 160 (see, e.g., the vent 200 of FIGS. 9A-9C or the vent
260 of FIGS. 10A-10C), in combination with the various tether 150
configurations shown and described herein, permit adaptation not
only with respect to how the vent is throttled in response to
occupant penetration, but also how the vent responds prior to
occupant penetration, the timing of the throttling response once
occupant penetration begins, and the vent response dependent upon
the vehicle/occupant conditions prior to penetration.
FIGS. 4A-4C illustrate the apparatus 10 in three conditions. FIG.
4A illustrates the apparatus 10 in a condition prior to the
occupant 20 engaging the air bag 14. In this condition, the vent
160 is fully actuated due to the air bag 14 reaching its fully
deployed condition. Also, in this condition, the occupant 20 is
spaced from the air bag 14 and must move forward in order to engage
and penetrate into the air bag 14. This distance can be measured in
terms of occupant chest to instrument panel (IP) distance, which is
indicated at D.sub.1 in FIG. 4A. The distance that the occupant 20
must travel before this engagement takes place can vary depending
on the occupant/seat position prior to air bag deployment.
FIG. 4B illustrates the apparatus 10 in a condition when the
occupant 20 initially engages the air bag 14, having moved forward
from the position illustrated in FIG. 4A. The chest to IP distance
when this occurs is indicated at D.sub.2 in FIG. 4B. At this point,
further occupant penetration into the air bag 14 moves the guide
156 which, through the resulting movement of the tether 150,
throttles the vent 160 toward the non-actuated condition. As
described previously herein, occupant penetration into the air bag
14 and rebound out of the air bag produces corresponding throttling
of the vent 160 toward the in the non-actuated and actuated
conditions, respectively, of the vent 160.
FIG. 4C illustrates the apparatus 10 in a condition when the
occupant 20 has fully penetrated into the air bag 14, having moved
forward from the position illustrated in FIG. 4B. The chest to IP
distance when this occurs is indicated at D.sub.3 in FIG. 4C. At
this point, the guide 156 has been moved by the penetrating
occupant 20 to the point where the tether 150 is slackened. In this
condition, the vent 160 has been fully throttled by the penetrating
occupant 20, thus placing the vent 160 in the non-actuated
condition.
According to the invention, the apparatus 10 has several
configurable features that help provide the multi-phase adaptive
venting functionality. FIG. 5 illustrates the multi-phase adaptive
venting functionality of the apparatus 10 of FIGS. 4A-4C, which
features a single guide 156 and the resulting two segment tether
150. The chart of FIG. 5 illustrates occupant penetration in terms
of occupant chest to instrument panel (IP) distance versus time,
where time=0 at the start of the impact event that triggers
deployment of the air bag 14. The various regions of the chart,
which are bounded by bold lines, indicate the various vent
conditions which, once the air bag 14 is deployed, depend on the
occupant chest to I/P distance. At time=0, the vent 160 is in the
non-actuated condition. Uninhibited, the vent 160 is configured to
transition to the actuated condition by time=20 ms. FIG. 5
illustrates how the apparatus 10 of the present invention is
configured between the three phases/conditions of vent
actuation--non-actuated, actuated, and throttling--in response to
the vehicle and occupant conditions that are gauged in terms of
occupant penetration, i.e., chest to instrument panel (IP)
distance.
The chart of FIG. 5 and the regions depicted thereon correspond to
the configuration illustrated in FIGS. 4A-4C. Thus, as shown in
FIG. 5, once the air bag 14 is deployed, occupant penetration
(i.e., chest to IP distance) from 600 mm to approximately 330 mm
will not affect the vent 160, and the vent will remain in the
actuated condition. Occupant penetration from approximately 330 mm
to approximately 270 mm will throttle the vent 160 from the
actuated condition toward the non-actuated condition. Once occupant
penetration reaches approximately 270 mm, the vent 160 reaches the
non-actuated condition and remains in the non-actuated condition as
long as the occupant penetration is approximately 270 mm or
less.
The various lines labeled A through G in FIG. 5 illustrate the
operation of the apparatus 10 in response to varying vehicle and
occupant conditions at the time of deployment of the air bag 14 of
FIGS. 4A-4C. The line identified at A in FIG. 5 corresponds to a
belted occupant 20 with a full forward seat position that produces
an initial chest to IP distance (see FIG. 4a) of approximately 380
mm. This would correspond to a belted 5% female occupant. As shown
in FIG. 5, the apparatus 10 is configured to respond to the full
forward belted occupant with the vent 160 transitioning quickly to
the throttling condition (i.e., within about 15 ms, at
time.apprxeq.35 ms, see FIG. 4B). The vent 160 throttles and
reaches the non-actuated condition within about 20 ms, at
time.apprxeq.55 ms). The occupant penetrates into the air bag 14,
reaching maximum penetration of about 220 mm chest to IP at
time.apprxeq.75 ms (see FIG. 4C). The occupant 20 then rebounds and
the vent 160 throttles at time.apprxeq.110 ms back to the actuated
condition at time.apprxeq.125 ms. If there is sufficient pressure
in the air bag 14, the vent 160 may throttle back to the actuated
condition. Any further impacts with the air bag 14 would thus occur
with the vent 160 in the actuated condition, and any further
ride-down would proceed with the vent throttling to the
non-actuated condition at the penetration values dictated by the
configuration of the apparatus 10 (i.e., throttling at.apprxeq.330
mm chest to IP, and non-actuated at.apprxeq.270 mm).
The line identified at B in FIG. 5 corresponds to an unbelted
occupant 20 with a full forward seat position that produces an
initial chest to IP distance of approximately 380 mm. This would
correspond to an unbelted 5% female occupant. As shown in FIG. 5,
the apparatus 10 is configured to respond to the full forward
unbelted occupant with the vent 160 transitioning quickly to the
throttling condition (i.e., within about 10 ms, at time.apprxeq.30
ms). The vent 160 throttles and reaches the non-actuated condition
within about 15 ms, at time.apprxeq.45 ms). The occupant penetrates
into the air bag 14, reaching maximum penetration of about 40 mm
chest to IP at time.apprxeq.90 ms. The occupant 20 then rebounds
and the vent 160 throttles at time.apprxeq.180 ms back toward the
actuated condition at time.apprxeq.200 ms. If there is sufficient
pressure in the air bag 14, the vent 160 may throttle back to the
actuated condition.
The line identified at C in FIG. 5 corresponds to a belted occupant
20 with a mid seat position between full forward and full rearward
that produces an initial chest to IP distance (see FIG. 4a) of
approximately 470 mm. This would correspond to a belted 50% male
occupant. As shown in FIG. 5, the apparatus 10 is configured to
respond to the mid positioned belted occupant with the vent 160
transitioning to the throttling condition (i.e., within about 35
ms, at time.apprxeq.55 ms, see FIG. 4B). The vent 160 throttles and
reaches the non-actuated condition within about 15 ms, at
time.apprxeq.70 ms). The occupant penetrates into the air bag 14,
reaching maximum penetration of about 200 mm chest to IP at
time.apprxeq.90 ms (see FIG. 4C). The occupant 20 then rebounds and
the vent 160 throttles at time.apprxeq.125 ms back to the actuated
condition at time.apprxeq.140 ms. If there is sufficient pressure
in the air bag 14, the vent 160 may throttle back to the actuated
condition. Any further impacts with the air bag 14 would thus occur
with the vent 160 in the actuated condition, and any further
ride-down would proceed with the vent throttling to the
non-actuated condition at the penetration values dictated by the
configuration of the apparatus 10 (i.e., throttling at.apprxeq.330
mm chest to IP, and non-actuated at.apprxeq.270 mm).
The line identified at D in FIG. 5 corresponds to an unbelted
occupant 20 with a mid seat position between full forward and full
rearward that produces an initial chest to IP distance of
approximately 470 mm. This would correspond to an unbelted 50% male
occupant. As shown in FIG. 5, the apparatus 10 is configured to
respond to the mid positioned unbelted occupant with the vent 160
transitioning to the throttling condition (i.e., within about 30
ms, at time.apprxeq.50 ms). The vent 160 throttles and reaches the
non-actuated condition within less than about 10 ms, at
time.apprxeq.55 ms). The occupant penetrates into the air bag 14,
reaching maximum penetration of about -30 mm chest to IP at
time.apprxeq.110 ms. The -30 mm penetration is indicative of the
unbelted occupant 20 impacting the instrument panel 36. The
occupant 20 then rebounds and the vent 160 throttles at time>200
ms back toward the actuated condition. If there is sufficient
pressure in the air bag 14, the vent 160 may throttle back to the
actuated condition.
The line identified at E in FIG. 5 corresponds to a belted occupant
20 with a full rearward seat position that produces an initial
chest to IP distance (see FIG. 4a) of approximately 560 mm. This
would correspond to a belted 50% male occupant. As shown in FIG. 5,
the apparatus 10 is configured to respond to the full rearward
belted occupant with the vent 160 transitioning to the throttling
condition (i.e., within about 50 ms, at time.apprxeq.70 ms, see
FIG. 4B). The vent 160 throttles and reaches the non-actuated
condition within about 10 ms, at time.apprxeq.80 ms). The occupant
penetrates into the air bag 14, reaching maximum penetration of
about 200 mm chest to IP at time.apprxeq.110 ms (see FIG. 4C). The
occupant 20 then rebounds and the vent 160 throttles at
time.apprxeq.135 ms back to the actuated condition at
time.apprxeq.150 ms. If there is sufficient pressure in the air bag
14, the vent 160 may throttle back to the actuated condition. Any
further impacts with the air bag 14 would thus occur with the vent
160 in the actuated condition, and any further ride-down would
proceed with the vent throttling to the non-actuated condition at
the penetration values dictated by the configuration of the
apparatus 10 (i.e., throttling at.apprxeq.330 mm chest to IP, and
non-actuated at.apprxeq.270 mm).
The line identified at F in FIG. 5 corresponds to an unbelted
occupant 20 with a full rearward seat position that produces an
initial chest to IP distance of approximately 560 mm. This would
correspond to an occupant leaning forward against the instrument
panel 36 at time=0. As shown in FIG. 5, the apparatus 10 is
configured to respond to the rear positioned unbelted occupant with
the vent 160 transitioning to the throttling condition (i.e.,
within about 40 ms, at time.apprxeq.60 ms). The vent 160 throttles
and reaches the non-actuated condition within less than about 10
ms, at time.apprxeq.70 ms). The occupant penetrates into the air
bag 14, reaching maximum penetration of about -100 mm chest to IP
at time.apprxeq.120 ms. The -100 mm penetration is indicative of
the unbelted occupant 20 impacting the instrument panel 36. The
occupant 20 then rebounds and the vent 160 throttles at time>200
ms back toward the actuated condition. If there is sufficient
pressure in the air bag 14, the vent 160 may throttle back to the
actuated condition.
The line identified at G in FIG. 5 corresponds to an out of
position occupant 20, e.g., a 50% male occupant leaning forward
against the instrument panel 36 at time=0. As shown in FIG. 5, the
apparatus 10 responds to the out of position occupant with the vent
160 remaining in the non-actuated condition from time=0 through
time.apprxeq.35 ms due to the out of position occupant inhibiting
air bag deployment. At time.apprxeq.35 ms, the vent 160 throttles
due to air bag deployment and the occupant moving away from the
instrument panel 36. At time.apprxeq.55 ms, the vent 160 reaches
the actuated condition and remains in this condition beyond
time=200 ms. Any further impacts with the air bag 14 would thus
occur with the vent 160 in the actuated condition, and any further
ride-down would proceed with the vent throttling to the
non-actuated condition at the penetration values dictated by the
configuration of the apparatus 10 (i.e., throttling at.apprxeq.330
mm chest to IP, and non-actuated at.apprxeq.270 mm).
The configuration of the vent 160 with the tether 150 and guide 156
shown in FIGS. 4A-4C is illustrative of one example implementation
of the invention. The configuration of the apparatus could vary.
For example, another implementation of the invention is illustrated
in FIGS. 6A-6C. The embodiment of FIGS. 6A-6C differs from the
embodiment of FIGS. 4A-4C only in that the guide is omitted,
leaving the tether connecting the vent directly to the air bag. In
describing the embodiment of FIGS. 6A-6C, the reference numbers
used in FIGS. 4A-4C will be utilized with the suffix "a" being
added to avoid confusion.
Referring to FIG. 6A, When the air bag 14a is fully inflated and
deployed, the tether 150a becomes fully tensioned and fully
actuates the vent 160a. The vent 160a is configured such that an
actuatable vent part (not shown in FIGS. 6A-6C) that controls fluid
flow through the vent is urged to move in response to inflation
fluid pressure in the air bag 14a. Inflation fluid pressure in the
air bag 14a urges the vent 160a toward the non-actuated condition.
The tether 150a is configured to such that tension on the tether
urges the actuatable vent part vent toward the actuated condition
against inflation fluid pressure in the air bag 14a. Thus, when the
air bag 14a is fully inflated and deployed, the tether 150a
overcomes the urging that inflation fluid pressure places on the
vent member and places the vent 160a in the fully actuated
condition. When the vent 160a is throttled due to occupant
penetration, the tether 150a is tensioned directly between the
front panel of the air bag 14a and the vent 160a.
Referring to FIG. 6B, the occupant 20a penetrates the air bag 14a
and begins displacing the tether 150a, which permits the actuatable
vent member to move in response to fluid pressure in the air bag
14a, thus throttling the vent 160a. As the vent 160a throttles
between the actuated and non-actuated conditions, the tension on
the tether 150a is maintained. As the degree of occupant
penetration increases, the throttling of the vent 160a adjusts
accordingly.
Referring to FIG. 6C, once the occupant 20a penetrates the air bag
14a to a degree such that the vent 160a is throttled to the
non-actuated condition, tension on the tether 150a is released. At
this point, since the vent 160a is in the non-actuated condition,
further penetration does not affect the vent. If, for some reason,
the occupant 20a moves in a direction that reverses the
penetration, and inflation fluid pressure in the air bag 14a is
still sufficient, the tether 150a could again become tensioned and
vent 160a throttling could resume.
The vent 160a may be an actuated open vent or an actuated closed
vent. Examples of actuated open and actuated closed vent types are
shown and described herein with reference to FIGS. 9A-9C and
10A-10C, respectively. The selection of a actuated open or actuated
closed vent configuration can be based on a variety of factors,
such as the position of the air bag (driver frontal/passenger
frontal) and the desired cushioning and ride down characteristics.
The actuated, non-actuated, and throttled conditions of the vents
of FIGS. 9A-9C and 10A-100 correspond to the vehicle and occupant
conditions illustrated in FIGS. 6A-6C according to table 2:
TABLE-US-00002 TABLE 2 Actuated Actuated Vent Open Vent Closed Vent
Corresponding Condition FIGS. 9A-9C FIGS. 10A-10C Figure Actuated
Open Closed FIG. 6A Throttled In Between In Between FIG. 6B
Non-Actuated Closed Open FIG. 6C
According to the present invention, the air bag 14a, vent 160a, and
tether 150a configurations disclosed herein advantageously are
configured and tailored for multi-phase adaptive venting. The
construction of the vent 160a (see, e.g., the vent 200 of FIGS.
9A-9C or the vent 260 of FIGS. 10A-10C), in combination with the
various tether 150a configurations shown and described herein,
permit adaptation not only with respect to how the vent is
throttled in response to occupant penetration, but also how the
vent responds prior to occupant penetration, the timing of the
throttling response once occupant penetration begins, and the vent
response dependent upon the vehicle/occupant conditions prior to
penetration.
FIGS. 6A-6C illustrate the apparatus 10a in three conditions. FIG.
6A illustrates the apparatus 10a in a condition prior to the
occupant 20a engaging the air bag 14a. In this condition, the vent
160a is fully actuated due to the air bag 14a reaching its fully
deployed condition. Also, in this condition, the occupant 20a is
spaced from the air bag 14a and must move forward in order to
engage and penetrate into the air bag 14a. This distance can be
measured in terms of occupant chest to instrument panel (IP)
distance, which is indicated at D.sub.1 in FIG. 6A. The distance
that the occupant 20a must travel before this engagement takes
place can vary depending on the occupant/seat position prior to air
bag deployment.
FIG. 6B illustrates the apparatus 10a in a condition when the
occupant 20a initially engages the air bag 14a, having moved
forward from the position illustrated in FIG. 6A. The chest to IP
distance when this occurs is indicated at D.sub.2 in FIG. 6B. At
this point, further occupant penetration into the air bag 14a moves
the tether 150a and throttles the vent 160a toward the non-actuated
condition. Occupant penetration into the air bag 14a and rebound
out of the air bag produces corresponding throttling of the vent
160a toward the in the non-actuated and actuated conditions,
respectively, of the vent 160a.
FIG. 6C illustrates the apparatus 10a in a condition when the
occupant 20a has fully penetrated into the air bag 14a, having
moved forward from the position illustrated in FIG. 6B. The chest
to IP distance when this occurs is indicated at D.sub.3 in FIG. 6C.
At this point, the occupant 20a has penetrated the air bag 14a to
the point where the tether 150a is slackened. In this condition,
the vent 160a has been fully throttled by the penetrating occupant
20a, thus placing the vent 160a in the non-actuated condition.
According to the invention, the apparatus 10a has several
configurable features that help provide the multi-phase adaptive
venting functionality. FIG. 7 illustrates the multi-phase adaptive
venting functionality of the apparatus 10a of FIGS. 6A-6C, which
features no guides and a single segment tether 150a. The chart of
FIG. 7 illustrates occupant penetration in terms of occupant chest
to instrument panel (IP) distance versus time, where time=0 at the
start of the impact event that triggers deployment of the air bag
14a. The various regions of the chart, which are bounded by bold
lines, indicate the various vent conditions which, once the air bag
14a is deployed, depend on the occupant chest to UP distance. At
time=0, the vent 160a is in the non-actuated condition.
Uninhibited, the vent 160a is configured to transition to the
actuated condition by time=20 ms. FIG. 7 illustrates how the
apparatus 10a of the present invention is configured between the
three phases/conditions of vent actuation--non-actuated, actuated,
and throttling--in response to the vehicle and occupant conditions
that are gauged in terms of occupant penetration, i.e., chest to
instrument panel (IP) distance.
The chart of FIG. 7 and the regions depicted thereon thus are
specific to the configuration illustrated in FIGS. 6A-6C. Thus, as
shown in FIG. 7, once the air bag 14a is deployed, occupant
penetration (i.e., chest to IP distance) from 600 mm to
approximately 330 mm will not affect the vent 160a, and the vent
will remain in the actuated condition. Occupant penetration from
approximately 330 mm to approximately 220 mm will throttle the vent
160a from the actuated condition toward the non-actuated condition.
Once occupant penetration reaches approximately 220 mm, the vent
160a reaches the non-actuated condition and remains in the
non-actuated condition as long as the occupant penetration is
approximately 220 mm or less.
The various lines labeled A through G in FIG. 7 illustrate the
operation of the apparatus 10a in response to varying vehicle and
occupant conditions at the time of deployment of the air bag 14a of
FIGS. 6A-6C. The line identified at A in FIG. 7 corresponds to a
belted occupant 20a with a full forward seat position that produces
an initial chest to IP distance (see FIG. 6A) of approximately 380
mm. This would correspond to a belted 5% female occupant. As shown
in FIG. 7, the apparatus 10a is configured to respond to the full
forward belted occupant with the vent 160a transitioning quickly to
the throttling condition (i.e., within about 15 ms, at
time.apprxeq.35 ms, see FIG. 6B). The vent 160a throttles and
reaches the non-actuated condition within about 35 ms, at
time.apprxeq.70 ms). The occupant penetrates into the air bag 14a,
reaching maximum penetration of about 220 mm chest to IP at
time.apprxeq.75 ms (see FIG. 6C). The occupant 20a then rebounds
and the vent 160a throttles at time.apprxeq.90 ms back to the
actuated condition at time.apprxeq.125 ms. If there is sufficient
pressure in the air bag 14a, the vent 160a may throttle back to the
actuated condition. Any further impacts with the air bag 14a would
thus occur with the vent 160a in the actuated condition, and any
further ride-down would proceed with the vent throttling to the
non-actuated condition at the penetration values dictated by the
configuration of the apparatus 10a (i.e., throttling at.apprxeq.330
mm chest to IP, and non-actuated at.apprxeq.220 mm).
The line identified at B in FIG. 7 corresponds to an unbelted
occupant 20a with a full forward seat position that produces an
initial chest to IP distance of approximately 380 mm. This would
correspond to an unbelted 5% female occupant. As shown in FIG. 7,
the apparatus 10a is configured to respond to the full forward
unbelted occupant with the vent 160a transitioning quickly to the
throttling condition (i.e., within about 10 ms, at time.apprxeq.30
ms). The vent 160a throttles and reaches the non-actuated condition
within about 20 ms, at time.apprxeq.50 ms). The occupant penetrates
into the air bag 14a, reaching maximum penetration of about 40 mm
chest to IP at time.apprxeq.90 ms. The occupant 20a then rebounds
and the vent 160a throttles at time.apprxeq.160 ms back toward the
actuated condition at time.apprxeq.200 ms. If there is sufficient
pressure in the air bag 14a, the vent 160a may throttle back to the
actuated condition.
The line identified at C in FIG. 7 corresponds to a belted occupant
20a with a mid seat position between full forward and full rearward
that produces an initial chest to IP distance (see FIG. 6A) of
approximately 470 mm. This would correspond to a belted 50% male
occupant. As shown in FIG. 7, the apparatus 10a is configured to
respond to the mid positioned belted occupant with the vent 160a
transitioning to the throttling condition (i.e., within about 35
ms, at time.apprxeq.55 ms, see FIG. 6B). The vent 160a throttles
and reaches the non-actuated condition within about 25 ms, at
time.apprxeq.80 ms). The occupant penetrates into the air bag 14a,
reaching maximum penetration of about 200 mm chest to IP at
time.apprxeq.90 ms (see FIG. 6C). The occupant 20a then rebounds
and the vent 160a throttles at time.apprxeq.110 ms back to the
actuated condition at time.apprxeq.140 ms. If there is sufficient
pressure in the air bag 14a, the vent 160a may throttle back to the
actuated condition. Any further impacts with the air bag 14a would
thus occur with the vent 160a in the actuated condition, and any
further ride-down would proceed with the vent throttling to the
non-actuated condition at the penetration values dictated by the
configuration of the apparatus 10a (i.e., throttling at.apprxeq.330
mm chest to IP, and non-actuated at.apprxeq.220 mm).
The line identified at D in FIG. 7 corresponds to an unbelted
occupant 20a with a mid seat position between full forward and full
rearward that produces an initial chest to IP distance of
approximately 470 mm. This would correspond to an unbelted 50% male
occupant. As shown in FIG. 7, the apparatus 10a is configured to
respond to the mid positioned unbelted occupant with the vent 160a
transitioning to the throttling condition (i.e., within about 30
ms, at time.apprxeq.50 ms). The vent 160a throttles and reaches the
non-actuated condition within about 10 ms, at time.apprxeq.60 ms).
The occupant penetrates into the air bag 14a, reaching maximum
penetration of about -30 mm chest to IP at time.apprxeq.110 ms. The
-30 mm penetration is indicative of the unbelted occupant 20a
impacting the instrument panel 36a. The occupant 20a then rebounds
and the vent 160a throttles at time>200 ms back toward the
actuated condition. If there is sufficient pressure in the air bag
14a, the vent 160a may throttle back to the actuated condition.
The line identified at E in FIG. 7 corresponds to a belted occupant
20a with a full rearward seat position that produces an initial
chest to IP distance (see FIG. 6A) of approximately 560 mm. This
would correspond to a belted 50% male occupant. As shown in FIG. 7,
the apparatus 10a is configured to respond to the mid positioned
belted occupant with the vent 160a transitioning to the throttling
condition (i.e., within about 50 ms, at time.apprxeq.70 ms, see
FIG. 6B). The vent 160a throttles and reaches the non-actuated
condition within about 20 ms, at time.apprxeq.90 ms). The occupant
penetrates into the air bag 14a, reaching maximum penetration of
about 200 mm chest to IP at time.apprxeq.110 ms (see FIG. 6C). The
occupant 20a then rebounds and the vent 160a throttles at
time.apprxeq.125 ms back to the actuated condition at
time.apprxeq.150 ms. If there is sufficient pressure in the air bag
14a, the vent 160a may throttle back to the actuated condition. Any
further impacts with the air bag 14a would thus occur with the vent
160a in the actuated condition, and any further ride-down would
proceed with the vent throttling to the non-actuated condition at
the penetration values dictated by the configuration of the
apparatus 10a (i.e., throttling at.apprxeq.330 mm chest to IP, and
non-actuated at.apprxeq.220 mm).
The line identified at F in FIG. 7 corresponds to an unbelted
occupant 20a with a full rearward seat position that produces an
initial chest to IP distance of approximately 560 mm. This would
correspond to an unbelted 50% male occupant. As shown in FIG. 7,
the apparatus 10a is configured to respond to the rear positioned
unbelted occupant with the vent 160a transitioning to the
throttling condition (i.e., within about 40 ms, at time.apprxeq.60
ms). The vent 160a throttles and reaches the non-actuated condition
within about 10 ms, at time.apprxeq.75 ms). The occupant penetrates
into the air bag 14a, reaching maximum penetration of about -100 mm
chest to IP at time.apprxeq.120 ms. The -100 mm penetration is
indicative of the unbelted occupant 20a impacting the instrument
panel 36a. The occupant 20a then rebounds and the vent 160a
throttles at time>200 ms back toward the actuated condition. If
there is sufficient pressure in the air bag 14a the vent 160a may
throttle back to the actuated condition.
The line identified at G in FIG. 7 corresponds to an occupant 20a
leaning forward against the instrument panel 36a at time=0. As
shown in FIG. 7, the apparatus 10a responds to the out of position
occupant with the vent 160a remaining in the non-actuated condition
from time=0 through time.apprxeq.25 ms due to the out of position
occupant inhibiting air bag deployment. At time.apprxeq.25 ms, the
vent 160a throttles due to air bag deployment and the occupant
moving away from the instrument panel 36a. At time.apprxeq.50 ms,
the vent 160a reaches the actuated condition and remains in this
condition beyond time=200 ms. Any further impacts with the air bag
14a would thus occur with the vent 160a in the actuated condition,
and any further ride-down would proceed with the vent throttling to
the non-actuated condition at the penetration values dictated by
the configuration of the apparatus 10a (i.e., throttling
at.apprxeq.330 mm chest to IP, and non-actuated at .apprxeq.220
mm).
The comparative examples of FIGS. 4A-5 and FIGS. 6A-7 illustrate
how the configuration of the apparatus 10 and 10a, respectively can
affect the functionality of the vent 160, 160a. By removing the
guide from the embodiment of FIGS. 4A-4C, the degree of penetration
required to throttle the vent 160, 160a from the actuated condition
to the non-actuated condition, and the range of penetration through
which this throttling occurs, is effectively doubled. The effective
area of the vent apertures in the vent 160, 160a determines the
volumetric flow rate of inflation fluid venting per unit
throttling/penetration distance. Thus, by adding/removing guides,
by changing the angle between tether segments in a configuration
that includes one or more guides, or through the construction of
the vent itself, the throttling effect on venting can be tailored.
This tailoring includes adjusting when the vent throttling begins
and ends, the amount of penetration required to begin throttling,
the amount of penetration required to completely throttle the vent,
and the rate at which inflation fluid flows through the vent during
throttling.
Viewing FIGS. 5 and 7, the apparatus 10, 10a of the present
invention is configured for multi-phase operation. Left uninhibited
during deployment, the vent 160, 160a is initially non-actuated and
transitions to the actuated condition upon reaching a predetermined
point during deployment. Thereafter, the vent 160, 160a is
responsive to vehicle and occupant conditions, and can throttle
between the actuated and non-actuated conditions depending on
occupant penetration.
Advantageously, the vent, being configured to assume the
non-actuated condition under the influence of inflation fluid
pressure, is initially non-actuated. Thus, by selecting an actuated
closed vent configuration, the air bag initially will vent, which
may be beneficial, for example, in a scenario where it is desirable
for the initial energy of the inflating air bag to be minimized.
Conversely, by selecting an actuated open vent configuration, the
air bag initially will not vent, which may be beneficial, for
example, in a scenario where it is desirable that the air bag
inflate and pressurize as rapidly as possible. If the vent does not
assume the non-actuated condition under the influence of inflation
fluid pressure in the air bag, this multiphase operation cannot be
achieved.
An additional advantage lies in the fact that by sizing the vent
and by configuring the tether and any included guide(s), the amount
of venting that occurs during throttling and the range of
penetration over which throttling occurs can also be tailored. For
example, a vent with a comparatively large vent opening in a
guideless configuration will result in a comparatively large
volumetric flow rate through the vent for a comparatively long
duration. Conversely, a vent with a comparatively small vent
opening in a configuration implementing one or more guides will
result in a comparatively small volumetric flow rate through the
vent for a comparatively short duration. Combinations of vent
sizes, guide configurations, and tether length and angles can be
incorporated to select the combination that yields the desired vent
rate and duration over the desired degree of occupant penetration.
From this, those skilled in the art will appreciate that these
properties can be combined in various manners to tailor both the
flow rate and the venting duration of the apparatus.
From the above description of the invention, those skilled in the
art will perceive improvements, changes and modifications. Such
improvements, changes and modifications within the skill of the art
are intended to be covered by the appended claims.
* * * * *